Balloon Race/Payload
Objective
To explore properties of propulsion and concepts of payloads while using scientific methods to derive the best techniques for winning races and transporting weights.
Terms to Know
Propulsion – To carry a load by airborne means
Payload – A weight or load that is to be carried (examples: in the space shuttle they often carry satellites, instruments, computers, etc)
Propellant – The gas escaping from a balloon in this experiment, which pushes the balloon along
Materials Used
1 length of 20-foot nylon string per group of 4 students
2 payload baskets made from empty water bottles and straws with velcro on the bottom for each group of 4 students
4 helium quality balloons for each group of 4 students
Process
Step 1- Preparation
String the strings between chairs or tables as shown in the diagram:
Where each arrow represents a segment of the 20 ft string. Two segments are equal to 20 feet. Essentially the one student is stationed at the first vertice, two at the next and one at the final vertice.
Thread a payload basket on each segment
Pull the chairs apart to make the string taught. Spread out with one person at each end.
Give each student a helium quality balloon. Ask them to inflate the balloon and attach it to the bottom of the payload bucket.
This is an empirical study to see what inflation provides enough energy to cross the span.
Step 2- Add the payload
The new challenge is to use this mechanism to carry a total weight of at least 120 grams from the initial node to the final one. Each student is to use their own balloon but they share the payload bucket between nodes. They must use the balloons and payload apparatus to transfer the weight.
Discovery point: Using a balance beam, determine how many marbles it takes to represent 120 grams of weight.
This is then a classroom competition to see which group can most expeditiously transfer at least 120 grams of marbles.
Balloon Collision Discussion Questions
How does the balloon provide the energy for the transport?
What can help you win this contest? (List at least three observations.)
Is it better to inflate the balloon a lot or a little and why?
Is it better to attach the balloon parallel to the straw or at an angle? Why?
What function is the string serving?
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